Compositions and methods for achieving improved physiological response to exercise

ABSTRACT

Disclosed here are novel compositions and methods which can be used to reduce or prevent adverse physiological effects of physical exercise or environmental exposure. The novel compositions comprise fluids containing water, sugar, electrolytes, and a substance which is non-toxic to man or animals, can be rapidly absorbed through the gastrointestinal tract, prevents decreases in blood volume, and acts as an energy source.

CROSS-REFERENCE TO A RELATED APPLICATION

This application is a continuation-in-part of our copending applicationSer. No. 226,027, filed July 29, 1988, now abandoned.

BACKGROUND OF THE INVENTION

In humans and other animals, strenuous exercise as well as exposure tosunlight and heat can result in significant physiological changes.Subjects exercising or working in the heat are at risk for developingheat related injuries. Environmental heat illnesses include heatsyncope, heat exhaustion, dehydration syndrome, and heat stroke. Thepotentially fatal clinical syndrome of heat stroke has been described inmarathon runners, military recruits, football players, and in hotindustrial environments. An epidemic appearance of heat stroke has beendescribed during heat waves in urban areas (Ferguson, M., and M. M.O'Brien [1960] "Heat Stroke in New York City: Experience with 25 Cases,"N.Y. State J. Med. 60:2531-2538).

The "dehydration syndrome" is characterized by loss of appetite andlimited capacity for work. Evidence of heat exhaustion becomes apparentwith losses of 5% of the body water, and at 7% disorientation andhallucinations occur. Losses of body water of 10% or greater areextremely hazardous and lead to heat stroke and death if not treatedimmediately. Heat stroke is accompanied by high body temperature(106°-110° F.), deep coma, and in most cases there is complete absenceof sweating, and failure of the major organ systems.

Three factors determine the thermal balance of the body: metabolic heatproduction, heat exchange between the organism and its surroundings, andheat loss by the evaporation of sweat (Knochel, J. P. [1980] "Clinicalphysiology of heat exposure," In Clinical Disorders of Fluid andElectrolyte Metabolism, M. H. Maxwell and C. R. Kleeman, eds.,McGraw-Hill, New York). For the subject exercising or working,particularly in a hot environment, the capacity to dissipatemetabolically produced heat depends for the most part on the subject'sability to form and vaporize sweat (Costill, D. L. and K. E. Sparks[1973] "Rapid fluid replacement following thermal dehydration," J. Appl.Physiol. 34(3):299-303; Greenleaf, J. E. [1979] "Hyperthermia andexercise," Int. Rev. Physiol. 20:157-208).

During exercise in a hot environment, serious deficits in effectivecirculating volume may occur. Muscular work, independent of environment,results in massive shunting of blood to skeletal muscle, along with asubstantial loss of plasma volume into the working muscle. Moreover,effective circulating volume is also diminished by losses of sweat(Knochel [1980] supra). The deficit in intravascular volume impedes thedelivery of heated blood to the periphery for evaporative cooling. Thus,in the dehydrated exercising subject, there is a progressive increase inthe core body temperature as sweat losses accumulate. Indeed, salt andwater depletion are important predisposing factors to the development ofheat-related illnesses.

Exercise is characterized by a marked increase in glucose utilization.The exercising muscle has a greatly increased need for energy. Some ofthe glucose needed for energy comes from liver glycogen stores. Withprolonged exercise, liver glycogen stores are depleted and the rate ofglucose production fails to keep pace with glucose utilization,resulting in a fall in the blood glucose concentration. The developmentof frank hypoglycemia has been described in marathon runners (Felig, P.,A. Cherif, A. Minagawa et al. [1982] "Hypoglycemia during prolongedexercise in normal men," N. Engl. J. Med. 306(15):895-900).

Notable among the many physiological responses to physical exertion areincreased body temperature, perspiration and pulse rate, a decrease inthe blood volume, and biochemical changes associated with the metabolismof compounds to produce energy.

One metabolic change which is associated with continued physicalexertion is a shifting of the type of compound used as the primaryenergy source. In the absence of physical exertion, the metabolism offat is a primary energy source for the body. During times of exertion,carbohydrates are increasingly used as a source of readily availableenergy. The body continues to utilize carbohydrates as a major source ofenergy during prolonged periods of exercise.

If, however, the exercise is particularly strenuous or long in duration,the supply of readily available carbohydrates may become depleted andthe body is forced to utilize another source of energy. The metabolismof proteins fills the energy void caused by the depletion ofcarbohydrates. Unfortunately, the metabolism of protein is not anefficient source of energy for the exercising individual. Proteinmetabolism results in the utilization of amino acids. This amino acidutilization can result in the depletion of essential amino acids in theplasma. The loss of amino acids can detrimentally affect the person oranimal in many ways. One detrimental effect of the depletion of aminoacids is a reduction on the body's ability to repair tissue which isdamaged in the course of the strenuous exercise.

Attempts have been made to counteract the adverse effects of strenuousexertion. For example, the consumption of water helps to maintain bodytemperature and blood volume. This technique has met with very limitedsuccess, however. Also, products have been developed recently whichcombine sugar and electrolytes with water. One well known example ofthis type of product is GATORADE™ which contains 21 millequivalents perliter (21 meq/l) of sodium, 2 meq/l potassium, and 6% sucrose. TheGATORADE™ composition is described in British Patent No. 1,252,781,which issued to Bradley et al. Other such compositions are known and aredescribed, for example, in U.S. Pat. Nos. 4,042 and 4,322,407.

It is well known that glycerol (glycerin) can be ingested safely.Limited clinical studies have suggested that glycerol, in solution withwater, may be used to induce hyperhydration (Riedesel, M. L., D. Y.Allen, G. T. Peake, and K. Al-Quattan [1987] "Hyperhydration withglycerol solutions," J. Appl. Physiol. 63(6):2262-2268). The work of theRiedesel group which was described in the 1987 publication has also beendescribed, in part, in other places. In a 1985 abstract and in a 1987abstract, Riedesel and coworkers reported that ingestion of anapproximately 23% glycerol solution in saline resulted in overhydrationof the subjects. The two abstracts had conflicting result regardingwhether sweat rates were increased (Lyons et al. [1987] "PhysiologicalCosts of Exercise Following Hyperhydration with Glycerol," TemperatureRegulation I (35-40), p. 323 [abstract]; Allen et al. [1985] Environ.Physiol. II [3713-3720] p. 1046 [abstract]). In a 1987 report to the AirForce, Riedesel reported overhydration of rats which were fed glycerol(Riedesel [1987] "Oral Glycerol Solutions as a Deterrent to DehydrationDuring Heat Exposure," Department of the Air Force Report, ADA118746).In a 1988 abstract Riedesel et al. again reported hyperhydration anddecreased urine output after glycerol ingestion (Meuli et al. [1988]Exercise II [1309-1314] p. a521).

Other researchers have also examined the effects of glycerol ingestion.Maughan and Gleeson found that ingestion of large amounts of glycerolafter a 36 hour fast did not significantly improve performance ofexercising subjects (Maughan et al. [1988] The Eur. J. Appl. Physiol.57:570-576). In fact, for one of the control groups, exercise durationafter glycerol ingestion was lower than after water ingestion alone.This 1988 article confirms earlier work by Gleeson and Maughan whichfound that ingestion of large amounts of glycerol did not enhanceexercise performance (Gleeson et al. [1986] The Eur. J. Appl. Physiol.55:645-653).

Researchers at Washington University School of Medicine have alsoexamined the effects of glycerol ingestion. In 1981 the WashingtonUniversity group reported that glycerol-fed rats had increasedendurance, apparently because glycerol protected against hypoglycemia(Terblanche et al. [1981] J. Appl. Physiol 50(1):94-101). Significantly,however, two years later the Washington group found that glycerol didnot increase endurance in man when administered according to theirprotocol (Miller et al. [1983] Medicine and Science in Sports andExercise 15(3):237-242). These published reports on the effects ofglycerol have revealed that ingestion of large amounts of glycerol canresult in decreased urine output and hyperhydration. Several studieshave specifically looked at the effect of glycerol on endurance, andeach of these studies has found that glycerol in large doses does notappear to increase endurance in man.

Much of the previous research has focused on the ability of glycerol tocause water retention. However, water retention alone has little or nocorrelation with enhanced endurance or physiological performance. Inorder to have a beneficial effect on endurance and performance, thewater must be appropriately allocated throughout the body. It is notenough to simply reduce urine output. Water must be available forsweating, cells cannot be dehydrated, and plasma volume must bemaintained. Only if these physiological objectives are met can enduranceand performance be enhanced. This enhancement of the physiologicalresponse to exercise and heat can be largely attributed to efficientcooling of the body.

Osmotic pressure is primarily responsible for the direction and rate ofmovement of water across membranes in the body. The general concepts ofosmosis and osmotic pressure are very well known chemical phenomenawhereby water moves across a semipermeable membrane in such a way as tomake its thermodynamic activity uniform across the entire system. Thus,water will move across a semipermeable membrane such that the net flowof water will be across the membrane into the fluid which initially hadthe highest concentration of solutes. The allocation of water betweendigestive organs, blood plasma, and cells depends upon the relativeosmotic pressures between these sites. Although it has been establishedthat the ingestion of massive amounts of glycerol results in theretention of water within the body, i.e., the rate of urine flow isdecreased, this observation alone produces no information as to whetherthe body's physiological responses to heat or physical exertion havebeen enhanced. For example, a large concentration of glycerol in thestomach or intestine can cause water to move across the gastrointestinalmembranes into the digestive tract. This might cause detrimentalresponses to physical exertion and heat exposure. Also, highconcentrations of glycerol in the blood plasma can cause water to leavethe cells and enter the plasma. Again, the resulting dehydration of thecells could have detrimental effects on the person or animal.

Studies where large amounts of glycerol have been administered in shorttime periods have not shown beneficial physiological effects. Theresearchers have observed water retention, but none have demonstratedany effect which would enhance endurance or lessen a persorn'sdiscomfort. These studies do not establish any relationship between theadministration of glycerol and actual physiological responses toexercise or heat exposure. Also, no studies have examined thephysiological effects of glycerol or related compounds in solution withcompounds other than water or saline.

Thus, the focus of glycerol research in the past has been primarily toachieve random generalized water retention. By contrast, the researchwhich has led to the subject invention concentrated on achievingappropriate water distribution within the body. This has led to theformulation of a novel composition which greatly enhances thephysiological response to physical exertion and heat exposure.

Although GATORADE™ does help to combat some of the negative effectsresulting from physical exertion, long distance runners and otherathletes who must endure long periods of strenuous exercise still sufferthe effects of decreased blood volume and a loss of energy-providingcarbohydrates.

The invention described here is a novel fluid composition whichsurprisingly and advantageously maintains blood volume at levels wellabove those observed in the absence of fluids or even with GATORADE™.The novel product has the additional advantage of providing an energysource. Further, users of the product report lower levels of perceiveddifficulty of exercise when the novel fluid composition is used.

BRIEF SUMMARY OF THE INVENTION

The subject invention relates to novel compositions and methods forameliorating the adverse physiological effects which can result fromphysical exertion and heat exposure. The subject invention can be usedwith humans and other animals. Described here is a novel fluidcomposition comprising

(a) water;

(b) electrolytic compound(s);

(c) sugar; and

(d) an additional compound which is characterized by:

(i) non-toxic to man or animals;

(ii) is rapidly absorbed through the gastrointestinal tract;

(iii) prevents the decrease of blood volume; and

(iv) is an energy source

wherein the concentration of said additional compound(s) is from about0.5% to about 10%.

One example of said additional compounds is glycerol. The compositionmay also contain pyruvate, which enhances the energy available forworking muscles. The presence of pyruvate improves performance and helpsto prevent the detrimental breaking down of protein as an energy source.

Also described here are unique methods, involving the use of the novelfluid composition, for ameliorating the adverse effects which can resultfrom physical exertion, heat exposure, exposure to cold, and blood loss.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood with reference to the followingdrawings in which:

FIG. 1 shows the changes in blood volume of three trials of humansubjects working at 75-80% of their maximal rate of oxygen uptake on abicycle ergometer. The trials are designated in the figure. One standarderror is set off at each mean. This figure shows that only the groupwhich was given IQ II (15 minutes before initiation of exercise [200ml], at 15 min, 45 min, and every half hour thereafter) was able tomaintain their blood volume during the period of exercise.

FIG. 2 shows that the pulse rate of the group receiving IQ II wasmaintained at a lower value than the other two trials during the courseof exercise. The trials are the same as those shown in FIG. 1. Onestandard error is set off at each mean.

FIG. 3 shows the high level of cardiac output achieved in connectionwith the administration of IQ II.

FIG. 4 shows the time required to reach a rectal temperature of 38° C.by the three trials shown in FIG. 1, as well as an additional groupreceiving nothing per os (NPO) prior to the exercise.

FIG. 5 shows the mean rates of sweating of the same four trials as inFIG. 3.

FIG. 6 shows the respiratory quotient ([CO₂ ]/[O₂ ]) as a function ofexercise time. Respiratory quotient is an indication of the metabolicenergy source being utilized.

FIG. 7 shows the perceived difficulty (in arbitrary rating units) of theexercise as scored by observers during the exercise.

DETAILED DESCRIPTION OF THE INVENTION

The invention described here is a novel composition which has been shownto improve the physiological response in animals, including humans, tophysical exercise and environmental exposure. Specifically, theinvention comprises a fluid which contains, as one of the ingredients,glycerol or an ester of glycerol, or any other analog or derivative ofglycerol which is non-toxic to animals, can be rapidly absorbed throughthe gastrointestinal tract, distributed into plasma and extracellularfluid, but is not transferred, or is transferred poorly, into the brain.As used hereinafter, the term glycerol refers to glycerol itself and anyester, analog, or derivative which has the same function as glycerol inthe composition described here. Instead of glycerol, or in addition toglycerol, the composition may contain pyruvate. Other compoundssatisfying the aforementioned characteristics can be found in standardmedical or pharmacology reference books.

The novel fluid's surprising and beneficial physiological effects on thebody during exercise or environmental exposure include maintenance ofblood volume and cardiac output, readily available energy source,improved skin blood flow, prevention or delay of onset of hyperthermia,increased rate of movement of electrolytes across the gastrointestinalwall, reduction in the breakdown of proteins and associated metabolismof essential amino acids, and decreased time needed for repair of bodytissue following strenuous exercise.

When the fluid of the subject invention is administered, the body'sphysiological response to exercise or environmental exposure is greatlyenhanced compared to the response when the body receives no fluids,receives only water, or receives fluid such as GATORADE™ which containelectrolytes and a sugar source in addition to water. Thus, the novelcomposition described here can be used to ameliorate the adverse effectsof physical exertion or environmental exposure. As used herein, the term"ameliorating the adverse effects of physical exertion or environmentalexposure" refers to the achievement of one or more of the following:prevention of plasma volume decrease, increased respiratory quotient,reduced rate of increase of rectal temperature, reduced pulse rate, orincreased cardiac output; combined with either enhanced endurance orperformance, lower perceived difficulty of a physical task, or anenhanced ability to withstand heat exposure or chronic exposure to cold.The many advantages of the novel fluid composition (designated IQ II)described here are clearly shown in FIGS. 1 through 7. The IQ II whichwas administered to exercising individuals in order to achieve theresults discussed below was primarily water. In addition to the water,the composition comprised glucose (4%), potassium (2 meq/l), sodium (26meq/l), phosphate (4 meq/l), and glycerol (3%).

One important advantage of IQ II is that it allows the body to maintainthe volume of blood at levels close to the pre-exercise volume. Evenwhere water or GATORADE™ are given to the exercising person, significantdecreases in blood volume are observed. The blood volume comparisons areshown in FIG. 1. FIG. 2 illustrates the ability of the novel fluidcomposition to prevent the elevation of heart rate to the level of thatobserved for subjects receiving either water or GATORADE™.

When the novel fluid composition is administered, cardiac output isadvantageously sustained at a high level, even over extended periods ofexertion. FIG. 3 illustrates this effect. Increases in body temperatureduring exercise occur much more slowly when the novel fluid compositionis given than when no fluids are administered or when either water ortraditional GATORADE™ are administered. FIG. 4 shows that, on theaverage, it takes more than 30% longer for rectal temperature to reach38° C. when IQ II is used than when GATORADE™ is used. It is possible toexercise for well over 1 hour at 75-80% of maximal rate of oxygenconsumption without reaching a body temperature of 38° C. when IQ II isadministered. Also, a marked decrease in the rate of sweating isobserved for individuals given the novel fluid composition of thesubject invention. This decrease in sweat rate is shown in FIG. 5. Thedecrease in sweat rate is significant because this suggests that thebody is being cooled more efficiently. This can be attributed toincreased blood volume which results in improved peripheral circulationand movement of blood near the skin surface. This surface circulation isvery important in the effective dissipation of body heat.

Further evidence suggests that the use of IQ II results in an increasein the proportion of energy derived from carbohydrates as opposed toenergy derived from the metabolism of fat or protein. This unexpectedand advantageous result can be seen from FIG. 6 which shows therespiratory quotient as a function of time. Respiratory quotient, whichis defined as the ratio of carbon dioxide output to oxygen input, is anindication of the type of compounds which are being metabolized as anenergy source for the exercising person or animal. For metabolism ofcarbohydrates, the respiratory quotient is 1.0. The respiratory quotientfor metabolism of fats or proteins is less than 1.0. If fat is theprimary source of energy, then the respiratory quotient is approximately0.6. A respiratory quotient of approximately 0.8 can be expected if thecells are burning half fat and half carbohydrates. Thus, the higherrespiratory quotients shown in FIG. 6 for IQ II indicate that theseindividuals are utilizing a greater proportion of carbohydrates as theirenergy source. The increased use of carbohydrates can have importantphysiological advantages, especially when strenuous exercise ismaintained over a long period of time. For example, carbohydratemetabolism is preferable to fat metabolism because it is a quicker andmore efficient source of immediate energy. Further, carbohydrates arepreferred as an energy source over proteins because protein metabolismcan cause the depletion of essential amino acids. The depletion of aminoacids can have adverse physiological effects including a reduction inthe body's ability to repair muscle which is damaged in the course ofexercise.

To further enhance the energy sources available to cells, pyruvate maybe added to the novel composition. It has also been found that byadministering pyruvate, it is possible to maintain a relatively steadyconcentration of pyruvate for use by cells as an energy source. Additionof a small amount of pyruvate, given at frequent intervals, improvesperformance and endurance, apparently because it enhances entrance ofacetyl CoA into the Krebs cycle. The Krebs cycle is a well known, butvery complicated, biochemical pathway which provides a working musclewith its energy source. A detailed description of the Krebs cycle can befound in most biochemistry textbooks, including Lehninger (Lehninger, A.J. Biochemistry: The Molecular Basis of Cell Structure and Function,2ed., Worth Publishers, Inc.: New York, pp. 444-449, 1975).

Pyruvate normally is formed from glucose but, during vigorous exercise,pyruvate may not be formed fast enough to keep up with cellular demand.Thus, the concentration of pyruvate drops markedly. This loss ofavailable pyruvate noot only deprives cells of their primarycarbohydrates energy source, but also inhibits the metabolism of fats asan energy source. Fats enter the Krebs cycle as acetyl CoA. Acetyl CoA,which is formed as a result of the breakdown of long chain fatty acids,apparently does not enter in the Krebs cycle, it is converted toaceto-acetic acid, which does not act as a ready energy source.Therefore, when pyruvate is available in short supply, the cells aredeprived of their primary carbohydrate source, and they cannoteffectively metabolize fats either. Thus, the cells can be forced todepend upon amino acid metabolism in order to derive energy. If theconcentration of pyruvate falls during vigorous exercise, no fuel canenter the Krebs cycle, and the cell, in effect, starves. Byadministering the novel composition described here, blood pyruvate isstabilized at a level sufficient to assure adequate energy supplies.

An additional important indicator of the novel fluid composition'seffectiveness is illustrated in FIG. 7. This figure shows a significantlowering of the perceived difficulty long term exercise amongindividuals to whom IQ II is administered. Although all individualsnaturally perceive an increase in difficulty of exercise as the exerciseis maintained for long periods of time, individuals who were given IQ IIshowed a significantly reduced rate of increase in the perceiveddifficulty of the exercise. The trial ingesting water showed the normalperceived difficulty within 90 minutes of begining exercise while in thetrial receiving GATORADE™ reached the same level of perceived difficultyafter 150 minutes of exercise. The trial receiving IQ II reached thislevel after 180 minutes. The lower difficulty perceived by individualsreceiving IQ II could lead to enhanced physical performance, especiallywhen long term exercise, such as marathons, are involved.

The novel fluid composition of the subject invention can be used toimprove the physiologic response of any animal undergoing exercise orbeing subjected to high temperature conditions. For example, humans,horses, dogs, mules, oxen, camels, elephants, sheep, cows, and pigs area few of the animals which can benefit from the administration of thenovel fluid composition described here. The fluid of the subjectinvention can also be used to alleviate or prevent dehydration which isknown to result from chronic exposure to cold temperatures.

The fluid of the subject invention can be administered to an animalorally, intravenously, or by any other means of conveying said fluidinto the tissues of the animal.

Following are examples which illustrate materials, methods andprocedures, including the best mode, for practicing the invention. Theseexamples are illustrative and should not be construed as limiting. Whereconcentrations are expressed as percentages, these percentages refer toweight ratios.

EXAMPLE 1

For use in humans or other animals which are about to undergo, areundergoing, or have recently undergone physical exercise, a novel fluidcomposition comprising water, a sugar source, electrolytes, and glycerolcan be administered orally.

The composition, which is predominantly water, may contain between about0.5% to about 5% glycerol. Preferably, the composition may contain about1% to about 1.5% glycerol. The sugar of the composition may be sucrose,glucose or other appropriate sugar compound. Specifically, thecomposition may have a glucose concentration of from about 2% to about8%. Preferably, the glucose concentration may be about 4%.

The electrolytes of the composition can be selected, for example, fromthe group consisting of sodium, potassium, phosphate, bicarbonate,sulfate, chloride, calcium, and magnesium. For example, the fluid maycontain from about 1 meq/l to about 5 meq/l potassium and from about 15meq/l to about 30 meq/l sodium. Preferably, the composition may containabout 2 meq/l potassium and about 26 meq/l sodium. Also, the compositionmay contain phosphate in concentrations varying from about 2 meq/l toabout 8 meq/l. Specifically, the phosphate concentration may be about 4meq/l.

The novel fluid may also contain citric acid, citrate, preservatives,flavorings, artificial sweeteners, vitamins, minerals, and othercompounds appropriate in a beverage of this type. The novel fluid mayalso be carbonated.

EXAMPLE 2

In order to provide a readily available source of energy for cells, thecomposition of the subject invention can contain pyruvate. It has beenfound that sufficient concentrations of pyruvate are necessary for theproper entrance of carbohydrates and fats into the Krebs cycle. Duringthe course of strenuous exercise, the concentration of pyruvateavailable to cells can decrease markedly. By ingesting pyruvate, it ispossible to maintain sufficient plasma concentrations so that the cellsare able to utilize pyruvate as an energy source and so that fats can beeffectively metabolized.

When glycerol at about 1% and pyruvate at about 1% are both added to anappropriate glucose-electrolyte solution so that the osmotic pressure ofthe solution does not exceed 400 milliosmol, performance and enduranceare enhanced. The level of enhancement achieved by the compositioncontaining glucose, electrolytes, glycerol, and pyruvate is beyond theeffect of the glucose-electrolyte solution alone, theglucose-electrolyte solution plus glycerol, or the glucose-electrolytesolution plus pyruvate. Best performance is achieved if the solution iskept between 300 and 350 milliosmol.

EXAMPLE 3

The composition of the subject invention may be designed for intravenoususe. Intravenous use may have application in humans and in otheranimals. In the case of humans, intravenous use may be necessary when,for example, a person has fainted or otherwise become unconscious as aresult of, for example, over-exertion and/or overexposure to sunlight,heat, or hemorrhage and loss of blood.

For intravenous application, no flavoring compounds would be present.Also, a neutral pH would be needed, therefore, no acidic compounds wouldbe present in concentrations sufficient to significantly alter the pH ofthe saline solution.

The composition of the subject invention can also be used as a temporarysubstitute for blood. For example, in trauma cases where there has beena large loss of blood, this fluid can be given to replenish the bloodvolume. Also, during heart surgery or other surgical procedures where aheart-lung machine is used, the novel composition can be used to primethe heart-lung machine, thereby helping the patient to maintain plasmavolume and to provide energy to help ameliorate the physiological traumaof surgery. Also, by maintaining vascular volume, complications such aspost-surgical acute renal failure can be minimized.

EXAMPLE 4

A fluid composition similar to that described in Example 1 may beadministered to animals which are subject to strenuous exercise such asraces and agricultural work. The exact composition of the fluid as wellas the concentrations of its components may depend upon what type ofanimal is receiving the treatment. The teachings of this documentcombined with the expertise of one skilled in the biological and medicalsciences would enable the practitioner to adjust the composition of thefluid in order to accommodate the needs of a particular animal.

The administration of the novel fluid could be orally, intravenously, orby other means capable of delivering the fluid to the tissues of therecipient animal. If the fluid is to be delivered orally, such acomposition could contain flavoring which would make the fluidattractive to the animal. For example, for horses, the fluid could beflavored with an oat extract.

EXAMPLE 5

To enhance the beneficial effects of the novel fluid compositiondescribed here, caffeine may be added. The concentration of caffeine mayrange from about 50 mg/l to about 5000 mg/l.

EXAMPLE 6

The novel fluid composition described here may also be used to helpmaintain the weight and health of agricultural animals subjected to heatstress. Heat stress may occur, for example, on the open range, in zoos,and during the transportation of animals.

The fluid may be administered in any of the ways previously described.If administered orally, the fluid may be combined with appropriateflavorings to make it attractive to the animals.

EXAMPLE 7

The novel fluid composition described here may also be used to alleviatethe effects of volume depletion which is a problem which has beenobserved in astronauts.

EXAMPLE 8

The use of glycerol in a beverage could also be used in areas of coldenvironment where it would reduce tissue damage due to frostbite andextreme cold. Such a glycerol beverage would allow distribution of theglycerol into the tissues, particularly in the extremities, fingers andtoes, which are affected most by crystallization in the tissues and bydiminished blood flow. Glycerol has been found to be distributedthroughout the body in ten minutes after ingestion; thus, it could beused to rapidly provide protection from extreme cold. This could beespecially useful, for example, for football players who must play incold climates, but who cannot or do not wish to wear gloves or otherprotective covering.

Also, it is well established that dehydration can be a serious problemwhich accompanies prolonged exposure to cold temperatures. Because thesubject composition can be utilized to achieve proper water allocationand prevent blood plasma volume depletion, it can be used to amelioratethe effects of dehydration caused by exposure to cold temperatures.Thus, the novel composition can be used advantageously by skiers or byarmy personnel in cold climates.

EXAMPLE 9

The optimal rate of administration of the novel composition describedhere can depend upon the physiological characteristics of the individualreceiving the fluid, the nature of the physical exertion or exposure,and the environmental conditions. However, a standard rate ofapplication would be approximately 170 to 260 ml of fluid every 15 to 20minutes, starting approximately 15 minutes before the exercise orexposure is commenced. If significant sweating is occurring, as would beexpected in hot environments or with physical exertion, the intake offluid should be adjusted so that the volume ingested approximates theamount of fluid lost through sweating. When the fluid is ingested toalleviate the dehydration accompanying prolonged exposure to coldtemperature, the quantity of fluid ingested may be less than that whichis necessary to achieve the desired effects in hot climates.

The ratio of ingredients in the composition may also be adjusted forchanging environmental or physiological conditions. For example, in coldweather, the composition may contain a greater concentration of glyceroland a reduced concentration of electrolytes. Also, for individuals whodesire a lower calorie drink, the sugar may be replaced with anartifical sweetener such as aspartame. For individuals who are concernedabout high blood pressure, the drink can contain reduced concentrationsof sodium.

EXAMPLE 10

The composition of the subject invention may also be prepared in adehydrated, powder, or concentrate form for convenience of sale orshipment. When formulated in this way, the product could bereconstituted by the addition of water. The preparation of such aproduct in the dehydrated, powder, or concentrate form is well known tothose skilled in the art. See for example, U.S. Pat. Nos. 4,042,684 and4,322,407.

We claim:
 1. In a beverage comprising water, sugar, and electrolytes, animprovement wherein said beverage further comprises glycerol in aconcentration of from about 0.5% to about 5.0%.
 2. The beverage,according to claim 1, wherein the concentration of said glycerol isabout 1.0%.
 3. In a beverage comprising water, sugar, and electrolytes,an improvement wherein said beverage further comprises pyruvate.
 4. Thebeverage, according to claim 3, wherein the concentration of saidpyruvate is about 1.0%.
 5. In a beverage comprising water, sugar, andelectrolytes, an improvement wherein said beverage further comprisescaffeine in a concentration of about 50 mg/l to about 5000 mg/l.
 6. In abeverage comprising water, sugar, and electrolytes, an improvementwherein said beverage further comprises one or more of the followingingredients: glycerol in a concentration of from about 0.5% to about5.0%; pyruvate; and caffeine in a concentration of from about 50 mg/l toabout 5000 mg/l.
 7. The beverage, according to claim 6, comprising thefollowing ingredients:

    ______________________________________                                        Ingredient    Approximate Concentration                                       ______________________________________                                        potassium     2            meq/l                                              sodium        26           meq/l                                              glucose       4%                                                              pyruvate      1%                                                              caffeine      150          mg/l                                               water         balance.                                                        ______________________________________                                    


8. A method for ameliorating the effects of physical exertion, saidmethod comprising the administration to a person in need of suchamelioration a composition of claim 7.